What is the basic building block of the nervous system?

• A. Glial cells
• B. Neurons
• C. Axons
• D. Synapses

Answer: (B)

Neurons are the basic building block of the nervous system. They are specialized for processing and transmitting information through electrical impulses and chemical signals. Each neuron has dendrites to receive input, a cell body to integrate it, and an axon to send impulses to other neurons. At synapses, neurotransmitters bridge communication to the next cell, allowing networks to form and signaling to propagate. Glial cells play essential supporting roles—providing insulation, nourishment, and cleanup—but they do not perform the signaling functions that define the neuron’s core activity. Axons and synapses are parts of the neuron and the sites of transmission, not the fundamental unit themselves. So the neuron is the primary building block because it combines reception, integration, and communication in a single signaling unit.